Blood sugar levels can be compared to an amusement park wild ride. If you are living with diabetes, you may be very familiar with the fact that after consuming a meal or snack, blood sugar levels tend to rise, and as time goes by without food, they eventually come down. The rate and extent to which blood sugar levels rise and drop means different things to our bodies and are influenced by our food choices. So, what can we use to choose foods that minimize spikes in our blood sugar levels?
Are All Carbohydrates Equal?
Carbohydrates are a key component of many foods like fruits, grains, milk products, and some vegetables. The building block of all carbohydrates is a sugar molecule, whether that be glucose, fructose, or galactose. So, what makes the carbohydrates in brown rice different from those in table sugar? While table sugar is a product of two sugar molecules coming together, the carbohydrates in brown rice are formed from long chains of these simple carbohydrates. The ability for foods to raise our blood sugar levels depends on how long it takes for our bodies to break down the carbohydrate food into its basic building blocks, as well as the complexity and combination of the sugar molecules that are present.
The Glycemic Index - The Basics
The glycemic index, GI for short, assigns a value between 0 to 100 to foods based on how slowly or quickly it raises your blood sugar levels compared to pure glucose (white sugar). Foods with lower GI values tend to take longer to break down and therefore raise blood sugar levels slowly. On the other hand, foods with a higher GI value tend to be digested quickly and are more likely to result in blood sugar spikes; similar to what happens after consuming white sugar.
Generally speaking, foods are said to have a lower GI value if the number is between 1 and 55. This means the sugar is released at a slower rate and ideally is where the majority of a person’s daily carbohydrate intake would come from. Foods that have a GI value greater than 70 result in spikes in blood sugar levels and, if consumed as a large part of one’s daily intake, may increase your risk of developing health conditions associated with diabetes. A GI value between 55-69 is considered medium, moderately resulting in blood sugar increases, and ideally consumed in moderation. To find out the GI values of various foods, click here.
Using the Glycemic Index to Make Healthier Food Choices
Using the GI is not as complicated as it may sound. It’s often the matter of substituting high GI foods with lower ones. An example of these substitutions could be replacing white rice with brown rice or bananas with mixed berries. Hint: Foods with a higher fiber content tend to have a lower GI value!
Benefits of Consuming Foods with a Low Glycemic Index
Research has found various benefits of using the GI to choose foods that are low on the scale. These foods not only prevent large spikes in blood glucose levels, but often come with other health benefits too, such as helping to achieve and maintain healthy body weight or decreasing the risk of developing specific cancers and cardiovascular disease. A simple tool with several benefits!
Limitations of the Glycemic Index
After reading this blog, you might begin to realize the usefulness of the GI, as its benefits extend beyond people living with diabetes to include just about anyone who wants to make healthier food choices. However, it’s important to note that being solely dependent on the GI in an attempt to adopt a healthy lifestyle is not sufficient. Why? Consider a baked potato versus french fries. Which one is the healthier option? You’d be correct to say baked potato because it is higher in fibre and packed full of nutrients. However, the GI would suggest otherwise! French fries have a lower GI value than baked potatoes. So, should you base your answer solely on the GI scale and consume french fries as a substitute for baked potatoes? Of course not! This example may have helped you appreciate that there are several factors, beyond the GI scale, that we need to consider when making healthy food choices. Foods with higher fat and protein contents will often result in a lower GI because these foods naturally take longer for the body to digest – slowing the release of sugar into the bloodstream. Therefore, it is recommended to consume unrefined carbohydrate-rich foods with unsaturated fats and lean protein to reduce glucose spikes.
Takeaway Message
It’s important to remember that people living with diabetes don’t have to eliminate carbohydrates from their diet. Carbohydrates provide our bodies with fuel that keeps us going throughout the day. However, not all carbohydrates have the same effect on our bodies, especially when it comes to raising our blood sugar levels. Use the glycemic index as a guide – while acknowledging that it’s not perfect – to choose carbohydrate-rich foods on the low end of the scale. Most importantly, use this tool with other knowledge, tips, and tricks, to maintain a healthy and well-balanced diet.
References:
Brand-Miller, J., Hayne, S., Petocz, P., & Colagiuri, S. (2003). Low–Glycemic index diets in the management of diabetes. Diabetes Care, 26(8), 2261.
Harvard Health Publishing. (2020, January 6). Glycemic index for 60+ foods. Harvard Health Publishing. https://www.health.harvard.edu/diseases-and-conditions/glycemic-index-and-glycemic-load-for-100-foods.
Richards, L. (2021, February 7). What are high and low glycemic index foods? Medical News Today. https://www.medicalnewstoday.com/articles/high-glycemic-index-foods.
Sievenpiper, J.L., Chan, C.B., Dworatzek, P.D., Freeze, C., & Williams, S.L. Diabetes Canada 2018 Clinical Practice Guidelines for the Prevention and Management of Diabetes in Canada: Nutrition Therapy. Can J Diabetes 2018;42(Suppl 1):S64-S79.
Vega-López, S., Venn, B. J., & Slavin, J. L. (2018). Relevance of the glycemic index and glycemic load for body weight, diabetes, and cardiovascular disease. Nutrients, 10(10), 1361.
Villines, Z. (2019, July 4). Glycemic index: Everything you need to know. Medical News Today. https://www.medicalnewstoday.com/articles/325660.
Zafar, M. I., Mills, K. E., Zheng, J., Regmi, A., Hu, S. Q., Gou, L., & Chen, L. (2019). Low-glycemic index diets as an intervention for diabetes: A systematic review and meta-analysis. The American Journal of Clinical Nutrition, 110(4), 891-902. https://doi.org/10.1093/ajcn/nqz149.
